When i move shower valve to hot, the water pressure drops. There is more cold water than hot. I have changed my moen valve before and this still happens. Good water any where else in the house including the master bath shower. House is 10 years old city water and have had this problem for the last 5+ years. Help! Mike

Your whole house is likely plumbed wrong so that it is impossible to have equal pressures of both hot and cold at your shower. If you had your home plumbed with aquapex using a radiator for the hot water and a radiator for the cold water and have the radiators fed with a 1 inch line you can have close to perfect pressures.

Not sure about your particular valve, but most newer shower valves have an anti-scald limiter that stops the handle from turning too far to the hot water side. Check for a ring or a pin under the handle that can be set in different positions. It will need to be moved clockwise to allow the handle to rotate farther to hot.

Hope that helps. If you have trouble finding it, try looking up a diagram for the valve model.

I think you are on the right track. The first thing I would do is change the cartridge. While you have the valve apart examine the inlet ports as good as you can to see if there is any mineral buildup. You can use a short length of a small gauge mallable wire to run into water ports to se if you can break anything loose. Another thing you can do is to turn supply stop on slightly while you have the valve disassembled to wash any particles out. Hope this helps you and thanks.

Moen and all shower valve manufacturers follow american federal guidelines. Hold the unit in your hand with the handle facing you - the left side is the hot water inlet and the right side is the cold water inlet.

no but you will get a cross conection problem

This is taken from the Moen manual. You can download it here:
http://www.moen.com/shared/pdf/instruction_sheets/ins162e.pdf
Balance Spool Maintenance
The precise and instantaneous pressure control illustrated has been
achieved through the balancing spool, which has been manufactured to
exacting tolerances.
During construction or valve installation, foreign material such as solder
flux, pipe cuttings sand, dirt or wood is unavoidably introduced into the
water system. Occasionally, however, rare, these foreign materials can
cause the balancing spool to become stuck temporarily between the
rough-in and trim-out operations. If this happens, it will be apparent at
the trim-out test, in that the valve will deliver only a small trickle of water
or it will deliver only hot or cold water. If this occurs, proceed as follows:
1. Make sure that both the hot and cold water service lines are ON. Also,
make sure that both screwdriver stop-check valves are open. The valve
WILL NOT OPERATE unless both supplies are ON.
2. If the valve still does not function properly, turn off both the hot and
cold supplies and remove the balancing spool, using a wide blade
screwdriver. The inner piston of the balancing spool should shake
back and forth freely. If this is not the case, jar the spool on either
end to remove the foreign material and free the spool. When the
spool is free, replace it; turn ON both water supplies and the valve
will function properly. If you are unable to free the inner piston,
replace the entire spool.

these valves can be adjusted by removing the handle and adjusting the white gear that regulates the hot and cold that come out, try going more to one way if it gets colder then go the other way.

You bet....Pressure at the building varys with large use...8-10am or 4-6 pm....What floor you on...Higher the more pressure you need...maybe a pump...or plugged press.balance system....Not a novice handyman job...

Hello, first if any water supply hot or cold is turned off, you will experience trickling as you mention. You must have both cold and hot in order to adjust the temperature on your valve. if you had a plumber intall this unit you should ask him to adjust it. Otherwise here is how:
Rotate the handle counterclockwise to stop and let water run till cold water is purged, check
temperature. Rotate handle to off, remove handle parts (see Disassembly in your manual) and temperature limit stop, rotate clockwise to decrease and counterclockwise to increase maximum hot water temperature, reinstall temperature limit stop and handle (TIP: Do not screw handle in until desired maximum temperature is achieved) Repeat steps until desired maximum
temperature is achieved

Replacing the cartridge should solve the problem, the balancing spool is stuck, replacing it will solve the problem. The valve should look like this http://www.moen.ca/shared/pdf/3170pt.pdf . I have unstuck the spools in the past, soaking it in white vinegar will help to remove build up.